Hi Cajunmillerboy
I have used the Seachem Reef Fusion 1 and 2 before
seems reasonably good to me
but if demand increases, SPS or clams etc are added and grow, in a 90 gallon set up, it may prove to be a less cost effective method of calcium/ alkalinity supplementation, than some of the dry formulas, or bulk ingrediants IME
but for a nano aquarium or a limited demand larger aquarium, it is a convenient and IME effective means of maintaining parameters
Steve